1IKQ

Pseudomonas Aeruginosa Exotoxin A, wild type


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.62 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.209 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Refined Crystallographic Structure of Pseudomonas aeruginosa Exotoxin A and its Implications for the Molecular Mechanism of Toxicity

Wedekind, J.E.Trame, C.B.Dorywalska, M.Koehl, P.Raschke, T.M.McKee, M.FitzGerald, D.Collier, R.J.McKay, D.B.

(2001) J.Mol.Biol. 314: 823-837

  • DOI: 10.1006/jmbi.2001.5195
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Exotoxin A of Pseudomonas aeruginosa asserts its cellular toxicity through ADP-ribosylation of translation elongation factor 2, predicated on binding to specific cell surface receptors and intracellular trafficking via a complex pathway that ultimate ...

    Exotoxin A of Pseudomonas aeruginosa asserts its cellular toxicity through ADP-ribosylation of translation elongation factor 2, predicated on binding to specific cell surface receptors and intracellular trafficking via a complex pathway that ultimately results in translocation of an enzymatic activity into the cytoplasm. In early work, the crystallographic structure of exotoxin A was determined to 3.0 A resolution, revealing a tertiary fold having three distinct structural domains; subsequent work has shown that the domains are individually responsible for the receptor binding (domain I), transmembrane targeting (domain II), and ADP-ribosyl transferase (domain III) activities, respectively. Here, we report the structures of wild-type and W281A mutant toxin proteins at pH 8.0, refined with data to 1.62 A and 1.45 A resolution, respectively. The refined models clarify several ionic interactions within structural domains I and II that may modulate an obligatory conformational change that is induced by low pH. Proteolytic cleavage by furin is also obligatory for toxicity; the W281A mutant protein is substantially more susceptible to cleavage than the wild-type toxin. The tertiary structures of the furin cleavage sites of the wild-type and W281 mutant toxins are similar; however, the mutant toxin has significantly higher B-factors around the cleavage site, suggesting that the greater susceptibility to furin cleavage is due to increased local disorder/flexibility at the site, rather than to differences in static tertiary structure. Comparison of the refined structures of full-length toxin, which lacks ADP-ribosyl transferase activity, to that of the enzymatic domain alone reveals a salt bridge between Arg467 of the catalytic domain and Glu348 of domain II that restrains the substrate binding cleft in a conformation that precludes NAD+ binding. The refined structures of exotoxin A provide precise models for the design and interpretation of further studies of the mechanism of intoxication.


    Related Citations: 
    • Mapping the Enzymatic Active Site of Pseudomonas aeruginosa Exotoxin A
      Brandhuber, B.J.,Allured, V.S.,G., Falbel T.,B., McKay D.
      (1988) Proteins 3: 146
    • Crystallization of Exotoxin A from Pseudomonas aeruginosa
      Collier, R.J.,McKay, D.B.
      (1982) J.Mol.Biol. 157: 413
    • Structure of Exotoxin A of Pseudomonas aeruginosa at 3.0-Angstrom Resolution
      Allured, V.S.,Collier, R.J.,Carroll, S.F.,McKay, D.B.
      (1986) Proc.Natl.Acad.Sci.USA 83: 1320
    • The Crystal Structure of Pseudomonas aeruginosa Exotoxin Domain III with Nicotinamide and AMP: conformational differences with the intact exotoxin
      Li, M.,Dyda, F.,Benhar, I.,Pastan, I.,Davies, D.R.
      (1995) Proc.Natl.Acad.Sci.USA 92: 9308


    Organizational Affiliation

    Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
EXOTOXIN A
A
613Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)Mutation(s): 0 
Gene Names: eta
EC: 2.4.2.36
Find proteins for P11439 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Go to UniProtKB:  P11439
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.62 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.209 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 59.520α = 90.00
b = 98.120β = 97.30
c = 58.260γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-12-12
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-01-31
    Type: Database references